Ignore WPE ... he's turned into the resident troll.
If your company wants you here and is agreeing to pay you what you want, AND can proove to immigration that the skills you bring in are not easily available to HK you'll be ok.
Hiten is correct, your gross package is more than 20K (I misread your initial post) so you'll be ok. I've heard that the average package they're looking for is HK$23K.